Protein dilution effect on thiouracil-seroalbumin interactions.
As the spectra and binding parameters calculated for the thiouracil-albumin interaction change with the protein concentration, a human seroalbumin conformational change depending on protein concentration has been suggested. This protein-conformational change is tested by dilatometry and viscosimetry. At low concentrations, albumin showed a greater thiouracil binding capacity and a second positive peak in its interaction with the drug, detected by difference spectroscopy. Both effects are due to a monomerisation of protein dimers and not to a conformational change depending on protein concentration. This monomerisation would imply a major accessibility of thiouracil and propylthiouracil to other binding sites on HSA.
Ochoa de Aspuru
E
E
Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Basque Country, Vitoria-Gasteiz, Spain.
Marquínez
M A
MA
Zatón
A M
AM
D001665:Binding Sites; D019281:Dimerization; D006801:Humans; D011485:Protein Binding; D011487:Protein Conformation; D012709:Serum Albumin / Q000378:metabolism*; D013053:Spectrophotometry; D013889:Thiouracil / Q000378:metabolism*; D014466:Ultraviolet Rays; D014783:Viscosity
D012709:Serum Albumin; D013889:Thiouracil